You could post a picture of the stator and also the coil, both can be removed easily.

You should ask for a wiring diagram and also a parts book from the manufacturer….do not assume they do not have one, maybe they do?

Then if they tell you they do not have one then ask them if they think that is ok? I would love to hear what their answer would be.

Both of the parts delivered would be nice, testing both a stator and coil is pretty straight forward, but both can also react to heat so you could take a hair dryer to them and see if the resistance changes, when they are hot.

Did you ask the mechanic what the readings were? Did you ask him how many winding it has, number of wires and bolts? That may have been a bit more of a test of legitimacy then where is it…or didn’t you know?